Drum-based printing systems frequently offer an effective solution to speed and reliability requirements imposed by mass printing applications. Accordingly, during recent years these printing systems have undergone a trend of continually increasing popularity and demand.
Many drum-based printing systems incorporate printheads designed to eject tiny droplets of liquid ink. In such systems, print media are typically loaded onto a drum and rotated past the printheads. As the print media rotates by the printheads, the printheads deposit the ink droplets on the print media in a specific pattern to form a desired image on the print media.
To obtain and maintain good printed image quality, many printheads require periodic cleaning to flush drying ink from the printhead nozzles. This periodic cleaning is known as decap spitting or decapping.
Decap spitting operations are generally performed by ejecting a number of ink droplets through the nozzles of the printheads into a special receptacle, known as a spittoon. The decap spitting operations in the printheads help maintain acceptable quality in printed products by ensuring that the first few drops ejected from each nozzle have an adequate trajectory and satisfactory optical density.
Throughout the drawings, identical reference numbers designate similar, but not necessarily identical, elements.